LHC Phenomenology of Z' and Z" bosons in the SU(4)_L \times U(1)_X little Higgs model

TL;DR

This paper investigates the mass limits and discovery prospects of two extra neutral gauge bosons, Z' and Z'', in an SU(4)_L imes U(1)_X little Higgs model, using LHC data and comparing with other models.

Contribution

It provides new mass exclusion limits for Z' and Z'' bosons in the SU(4)_L imes U(1)_X little Higgs model and discusses their discovery potential at future LHC runs.

Findings

Lower mass limit for Z' is about 3 TeV.

Lower mass limit for Z'' is about 5 TeV.

Potential to discover Z' and Z'' at 14 TeV LHC.

Abstract

We examine direct limits on masses of the extra neutral gauge bosons in the SU(4)_L \times U(1)_X model with a little Higgs mechanism confronted with the LHC data, especially by embedding anomaly-free set of fermions. There exist two extra neutral gauge bosons, calling Z' and Z", in this model. The lower exclusion limit of the mass of the lighter extra neutral gauge boson is about 3 TeV while that of the heavier one 5 TeV. For comparison, we examine the mass limit of Z'_3 boson in the SU(3)_L \times U(1)_X model as well, and discuss the implication of our result in the SU(4)_L \times U(1)_X model with a standard Higgs mechanism. We also discuss the discovery potential of Z' and Z" at the future LHC with the center-of-momentum energy of 14 TeV. Our results can be applicable to the models with regular Higgs mechanism if the same type of fermion family is assigned.